Cryo-EM structures of a serotonin gated ion channel

血清素门控离子通道的冷冻电镜结构

基本信息

批准号：
9011376
负责人：
David Bulkley
金额：
$ 5.61万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-02-01 至 2017-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9011376
关键词：
Acetylcholine Acids Address Adverse effects Affinity Agonist Antiemetics Architecture Binding Binding Sites Biochemistry Biological Response Modifier Therapy Biophysics Collaborations Complex Cryoelectron Microscopy Crystallization Drug usage Emetics Environment Family Family member Gated Ion Channel Goals Health Homo In Vitro Ion Channel Label Laboratories Ligands Light Lipids Mediating Membrane Membrane Proteins Modeling Molecular Conformation Nervous system structure Neurodegenerative Disorders Neurotransmitters Nootropic Agents Pharmaceutical Preparations Pharmacology Play Property Resolution Role Sampling Series Serotonin Serotonin Receptors 5-HT-3 Signal Transduction Structure Synapses System TRPV1 gene Training Variant Work cancer therapy chemotherapy design gamma-Aminobutyric Acid hypnotic in vivo insight macromolecule member novel particle receptor receptor function receptor structure function reconstitution research study response sedative serotonin 5 receptor serotonin receptor

项目摘要

DESCRIPTION (provided by applicant): Pentameric ligand-gated ion channels (pLGICs), i.e. cys-loop receptors, represent a major family of receptors in the nervous system that mediate rapid excitatory or inhibitory responses in synapses. Cys-loop receptors are targets of clinically important drugs such as sedative hypnotics, cognitive enhancers used in the treatment of neurodegenerative diseases, and anti-emetics used in cancer treatment. Despite their biological and therapeutic importance, atomic structures of many members of this family, including the serotonin receptor (5-HT3), are unknown and the structural mechanisms underlying pLGIC activation remain unresolved. My goal is to break this barrier by determining a series of atomic structures of the 5-HT3 receptor using single-particle cryo-electron microscopy (cryo-EM). My project will rely on the close collaboration between the labs of Yifan Cheng and David Julius here at UCSF, which recently led to the determination of a series of structures of the TRPV1 ion channel at near- atomic resolution (3-4 Å) using single particle cryo-EM. Having established a similar collaboration, David Julius' lab will provide training in membrane protein biophysics and biochemistry, enabling me to identify 5-HT3 variants with properties suitable for high resolution structural work. Making use of the Cheng lab's expertise in single particle cryo-EM, we will then determine high resolution structures of the 5-HT3 receptor in various functional states, including apo-, agonist- and antagonist-bound states, and resolve the binding sites and mechanisms of action of various 5-HT3 agonists and antagonists. Finally, experiments will be carried out to determine the arrangement of subunits within heteromeric 5-HT3, probe the consequences of lipid composition on 5-HT3 structure and function, and determine high resolution structures of these complexes. The experiments proposed in this project will show the structural transitions involved in channel gating, providing an atomic resolution model of 5-HT3 activation and also shedding light on the mechanism of Cys-loop receptors in general. Because activation of the 5-HT3 receptor causes many of the emetic side effects associated with chemotherapy, our studies will also provide a structural framework for the rational design of novel antiemetic drugs and chemotherapeutics with reduced side effects.

描述（由申请人提供）：五聚体配体门控离子通道（pLGIC），即半胱氨酸环受体，代表神经系统中介导快速兴奋性或抑制性反应的主要受体家族，突触受体是半胱氨酸环受体的靶标。临床上重要的药物，例如镇静催眠药、用于治疗神经退行性疾病的认知增强剂以及用于癌症的止吐药尽管其生物学和治疗重要性，但该家族的许多成员（包括血清素受体（5-HT3））的原子结构尚不清楚，并且 pLGIC 激活的结构机制仍未解决。我的目标是通过确定 a 来打破这一障碍。使用单粒子冷冻电子显微镜（cryo-EM）研究 5-HT3 受体的一系列原子结构我的项目将依赖于 Yifan Cheng 和 David Julius 实验室之间的密切合作。加州大学旧金山分校最近使用单粒子冷冻电镜以近原子分辨率 (3-4 Å) 确定了 TRPV1 离子通道的一系列结构。在建立了类似的合作之后，David Julius 的实验室将提供培训。在膜蛋白生物物理学和生物化学方面，我能够识别具有适合高分辨率结构工作的特性的 5-HT3 变体，然后利用 Cheng 实验室在单粒子冷冻电镜方面的专业知识，我们将确定 5-HT3 的高分辨率结构。研究不同功能状态下的5-HT3受体，包括apo结合状态、激动剂结合状态和拮抗剂结合状态，并解析各种5-HT3激动剂和拮抗剂的结合位点和作用机制，最后进行实验以确定其排列。异聚 5-HT3 内的亚基，探讨脂质组成对 5-HT3 结构和功能的影响，并确定这些复合物的高分辨率结构。该项目中提出的实验将显示通道门控中涉及的结构转变，从而提供。 5-HT3 激活的原子分辨率模型，也揭示了 Cys 环受体的一般机制，因为 5-HT3 受体的激活会导致许多与化疗相关的呕吐副作用，我们的研究还将提供一个结构。合理设计新型止吐药物和副作用减少的化疗药物的框架。